Change of the Volatile Compounds from Celery Leaves during Storage Based on HS-SPME-GC-MS and E-nose

Headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and electronic nose (E-nose) were performed to investigate change of volatile compounds in celery leaves during storage at 20.0 ℃. The results indicated that a total of 108 volatile compounds were identified by HS-SPME-GC-MS, mainly including monoterpenes (43.2%~52.92%) and phthalides (19.93%~28.97%), in which D-limonene was abundant (6600.64~48566.12 μg/kg). The total volatile substance content of fresh celery was 165682.48 μg/kg, which decreased by 40.92% after 9 days of storage. The percent of monoterpenes and phthalides decreased by 9.72% and increased by 8.98% respectively during storage. In celery leaves, 31 substances were detected according to OAV>1. There were 31 kinds of the same characteristic volatile substances during 0~7 d and the number of characteristic volatile substances decreased to 29 at 9 d. During storage, the total OAV value decreased. The cluster analysis confirmed that the celery leaves were mainly minty and grassy odour during 0~3 d, and sweet, wood and camphorated odour at 7 d. After the 9th day, the aroma of celery leaves was spicy and herbal odour. The PCA of E-nose response data showed that E-nose could distinguish the aroma of celery leaves during different storage period. Based on Pearson correlation analysis, the main substances causing changes in the response value of E-nose were terpenoids, alcohols and aromatic volatile compounds of celery (r≥0.80, P<0.05). This study elucidates the changes of composition and content of volatile substances in celery leaves during storage, providing theoretical basis for judging the freshness of celery during storage.